View Full Version : Electric -Tungsten carbide hard edge tool

12-19-2012, 03:09 PM
Someone left this with me wondering if it was of some use to me. As he described it I remember seeing Mc Snody using one, and thought nah probably not for me as i'm using fine grained steels and fine edges which are easy to sharpen....but nether the less I had to have a fiddle.
Here is the kit which thankfully came with instructions, tungsten electrodes and everything required.
Rather unfortunate name, for the eighties...interestingly in the paperwork they had added a note to the purchaser informing him that they were just changing it to something else, very wise:C
Got a foot pedal, earth plate, electrode holder, and about half a dozen electrodes.
Some of the instructions and documents.
Sales Receipt

So I tried it on one from the scrap bin. You can control various things with the knobs, spark rate and power, to control depth and coverage to a degree. I turned it right down to do the very edge of the edge then pumped up the jam and moved back from the edge.


I had wondered weather it best to fully hone the edge first as I thought it may be tough on the waterstones after, however having got it home I honed a tiny bevel on there relatively easily, what is more it does also strop keen after honing.

The edge is aggressively toothy as I suspected, but still gets very sharp in a toothy way, I would not want to shave my face with it. I hacked into a brass rod with it and hit the rod on the edge in a few places, the thin edge showed very feint ripples of distortion but remained sharp. The distortion seemed limited to the tiny honed part and was so subtle it came out in a single pass on a 5 k stone.
So it does not behave like a tungsten alloy but as you would expect like a piece of steel with a web of very hard spots to a limited surface depth.

On cutting, the ability for the steel to push cut is noticeably reduced, but on the slice it feels good.

Its interesting.... and I may end up finding some use for it on very hard use mono steel kitchen tools or at the very least doing some further testing of advantages vs limitations... it will certainly come in handy for drill bits and cutters, maybe even some hot work tools and dies.

If anyone has any experience of these tools/knives with tungsten carbide treated edges or indeed a more in depth metallurgical insight I would find it very interesting.:)

Thoughts on a hard use kitchen tool which would benefit from a courser grain would also be appreciated in order to give it a testing.
I'm thinking of a honesuki chicken wacker :D

12-19-2012, 03:14 PM
Nice work for your first carbide edge--and the first review I've read that actually talks about how the edge performs on the stones and in the kitchen.

12-19-2012, 03:22 PM
Cheers, it did not seem to hard to do, I think the tool is a very well made one :biggrin: I've not really looked into it before trying this out, are there commercial kitchen knife companies using this technique?

12-19-2012, 04:31 PM
That looks like an interesting toy Will. How long did it take to do?

12-19-2012, 04:37 PM
With a bit of goggle fu I found some info about applying this technique to knives. It looks like I should have only set a bevel on one side, though the surface of the tungsten side can be smoothed to a degree so next time I will try coating one side only with the very finest of micro bevels just to smooth the surface of the tungsten coating, bevel set on the steel side and further sharpening from that side only so as to keep a constant layer of tungsten on the edge.
Judging by the way this edge behaves the tungsten penetrated as its so thin, but maybe only to a degree and further sharpening on both sides will reduce the tungsten penetrated layer.
So there are some limitations of bevel design and practical implications for thinning down the road though in theory wear and the need for sharpening should be reduced... I will have to do a long term test me thinks. it would seem most suitable to single bevel or a biased final bevel.

12-19-2012, 04:44 PM
Hello Tim, not too long, the machine can do 1cm square per minute. I did both sides of the edge and It looks like it should be done on one side only.:D
Its quite a tool, the electrode holder vibrates so as to make and break contact with the work, if you hold on to it too hard the electrode sticks to the work.
I hadn't really planned on keeping it...but I think im going to have to now to get to the bottom of it.:biggrin:

12-19-2012, 05:49 PM
Will, you see a lot of people using similar but simpler/cheaper machines to put a bit of a carbide coat on the face of the lock bar of titanium liner and frame lock folders where it contacts the harder locking surface of the blade.

11-01-2013, 08:47 AM
Hi Will,

any further testings done? interested to know as to whether after putting the tungsten carbides, how difficult will it be to sharpen it when required.

b) I stumbled upon a web-site selling knives ( can't find it now) and he does offer this service with the machine mentioned below.


Seems that this machine ( US Made) is specially made for knife makers..


any information forth coming will be much appreciated.


11-01-2013, 02:35 PM
I sold the machine to a guy who makes outdoor type knives and wanted to play with it. Very interesting machine, but a bit of a relic with the steels we have available to us today and really the edge was very very crude, basically a really hard brittle layer on one side of the blade that stays sharp as the rest of the soft steel wears away, but think thin jagged edge as it wears... though it would last a long time, but not something I would ever really use beyond the novelty factor.:D

11-01-2013, 03:13 PM
tks will and hv a nice week-end,,

as always rgds